1. Field of the Invention
The present invention relates to Co-based alloys for biomedical applications and in particular, to Co-based alloys for biomedical applications which are suitably provided for use of medical equipment such as equipment embedded-in a living body and equipment which has contact with the living body. In addition, the present invention relates to a stent.
2. Description of the Related Art
For alloys which are used for medical equipment embedded-in a living body or for medical equipment used while being in direct contact with the surface of the living body, high corrosion resistance and biocompatibility are required. Furthermore, with respect to alloys for a stent for securing blood flow by expanding coarctation site of a blood vessel within a living body, high intensity and high elastic modulus are required.
As Co-based alloys for biomedical applications which satisfy such requirements described above, alloys which consist primarily of Co-20 Cr-15W-10Ni (ASTM standard F90), alloys which contain the following, Co: 30% to 60%, Ni: 4% to 20%, Cr: 13% to 25%, C: equal to or less than 0.3%, Si: equal to or less than 2.0% and Mn: equal to or less than 2.0% or the like are well known (refer to PTL 1).    Patent Literature: [PTL 1] JP-A-2007-162121